Mold assemblies including removable inserts and associated methods of use and manufacture

ABSTRACT

Mold assemblies and associated methods and components for forming battery grids for lead acid batteries are disclosed herein. In one embodiment, a battery grid mold assembly includes a first die block that is movable relative to a second die block between an assembled position and an unassembled position spaced apart from the second die block. The mold assembly also includes a first insert plate having a first side that is removably coupled to the first die block and a second side opposite the first side. The second side of the first insert plate includes a first recess. The mold assembly further includes a second insert plate having a third side removably coupled to the second die block and a fourth side opposite the third side. The fourth side includes a second recess. When the first and second die blocks are in the assembled positions, the first and second recesses at least partially define a grid cavity that is configured to receive a flowable material for forming a battery grid.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/296,447, filed Jan. 19, 2010, and U.S. Provisional Application Ser. No. 61/348,671, filed May 26, 2010, the disclosures of which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The following disclosure relates generally to mold assemblies for producing lead components and, more specifically, to mold assemblies and associated removable inserts for producing battery grids for lead acid batteries.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an isometric front view of a portion of a mold assembly configured in accordance with an embodiment of the disclosure.

FIG. 1B is an exploded view of the portion of the mold assembly of FIG. 1A.

FIG. 1C is a schematic isometric view of the portion of the mold assembly portion of FIGS. 1A and 1B opposite a corresponding portion of a mold assembly.

FIG. 2A is a front view, FIG. 2B is a top view, FIG. 2C is a rear view, and FIG. 2D is a bottom view of a die block configured in accordance with an embodiment of the disclosure.

FIG. 3A is a top view of a fill plate configured in accordance with an embodiment of the disclosure.

FIG. 3B is a cross-sectional side view taken substantially along lines 3B-3B of FIG. 3A.

FIG. 3C is a rear view, FIG. 3D is an enlarged detail view, FIG. 3E is a right side view, FIG. 3F is a left side view, and FIG. 3G is a bottom view of the fill plate of FIG. 3A.

FIG. 4A is a front view, FIG. 4B is a bottom view, and FIG. 4C is a rear view of an insert plate configured in accordance with an embodiment of the disclosure.

FIG. 5A is a front view of an insert plate configured in accordance with another embodiment of the disclosure.

FIGS. 5B and 5C are enlarged detail views of a portion of the insert plate of FIG. 5A.

FIG. 5D is an isometric view of a portion of the insert plate of FIG. 5A.

FIG. 5E is a rear view and FIG. 5F is a top view of the insert plate of FIG. 5A.

DETAILED DESCRIPTION

The following disclosure describes mold assemblies and associated mold components for producing lead parts, such as battery grids for use in lead acid batteries. As described in greater detail below, a mold assembly configured in accordance with one aspect of the disclosure includes removable insert plates that are releasably secured to corresponding die blocks. The removable insert plates, rather than the die blocks, form a cavity for casting (e.g., gravity casting) a battery grid. Certain details are set forth in the following description and in FIGS. 1A-5F to provide a thorough understanding of various embodiments of the disclosure. However, other details describing well-known structures and systems often associated with lead mold assemblies, mold components and batteries, and/or other aspects of mold or die systems are not set forth below to avoid unnecessarily obscuring the description of various embodiments of the disclosure.

Many of the details, dimensions, angles, and other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. In addition, those of ordinary skill in the art will appreciate that further embodiments of the disclosure can be practiced without several of the details described below.

In the Figures, identical reference numbers identify identical or at least generally similar elements. To facilitate the discussion of any particular element, the most significant digit or digits of any reference number refers to the Figure in which that element is first introduced. For example, element 110 is first introduced and discussed with reference to FIG. 1A.

FIG. 1A is an isometric front view of a portion of a mold assembly 100 (“assembly 100”) configured in accordance with an embodiment of the disclosure. FIG. 1B is an exploded view of the assembly 100 of FIG. 1A. Referring to FIGS. 1A and 1B together, and as described in detail below, the assembly 100 is configured for casting (e.g., gravity casting) lead battery components, such as lead battery grids for lead acid batteries. More specifically, the assembly 100 includes a first mold part or die block 110 secured to a second mold part or fill plate 130. The assembly 100 also includes a third mold part or insert plate 150 secured to the die block 110 adjacent to the fill plate 130. In the illustrated embodiment the fill plate 130 is a separate component from the insert plate 150. In other embodiments, however, the fill plate 130 and the insert plate 150 can be a single integral component. As described in detail below with reference to FIG. 4A, the insert plate 150 includes a recess or cavity 152 for forming battery components, such as battery grids.

As will be understood by one of ordinary skill in the art, the assembly 100 shown in FIGS. 1A and 1B illustrates one half (e.g., the ejector half) of a complete die mold. Accordingly, the assembly 100 can also include a corresponding image second half assembly (e.g., a mirror-image assembly) that includes a second die block, a second fill plate, and a second insert plate, each of which is configured to mate or otherwise align with their corresponding components shown in FIGS. 1A and 1B. Therefore, the features of the assembly 100 illustrated in FIG. 1 and described herein (with the possible exception of the ejectors described below) are also included in the corresponding components of the second half of the assembly. FIG. 1C, for example, schematically illustrates the assembly 100 opposite a corresponding second assembly 100′ configured to mate with the assembly 100.

In one aspect of the embodiment illustrated in FIGS. 1A and 1B, the insert plate 150 and the fill plate 130 are separate components that are releasably attached to the die block 110. More specifically, and as illustrated in FIG. 1B, the assembly 100 includes fill plate alignment features 171 (e.g., alignment pins or studs) that extend from the die block 110 and that are received in the fill plate 130 to position the fill plate 130 on the die block 110. The assembly 100 also includes insert plate alignment features 172 (e.g., alignment pins or studs) that extend from the die block 110 and that are received in corresponding alignment openings 173 in the insert plate 150 to position the insert plate 150 on the die block 110. Once the insert plate 150 and fill plate 130 are correctly positioned, they are attached to the die block 110 with suitable fasteners, such as bolts, screws, etc. More specifically, the assembly 100 includes multiple fasteners 174 that extend through fastener openings 175 in the insert plate 150 and the fill plate 130 to reach corresponding threaded fastener openings 176 in the die block 110.

In the illustrated embodiment, the assembly 100 also includes multiple ejectors 180 extending through the die block 110 and corresponding portions of the insert plate 150 and fill plate 130. The ejectors are movable relative to these components to eject a finished casting from the assembly 100 following a casting process. For example, the ejectors 180 can be spring-loaded plungers, hydraulic plungers, etc. that are actuated or otherwise moved to push a part (e.g., a lead grid) out of the insert plate 150 after casting.

According to yet another aspect of the illustrated embodiment, the assembly 100 includes multiple biasing members 178 (e.g., coil springs) positioned between the die block 110 and the insert plate 150. The biasing members 178 are configured to push or bias the insert plate 150 away from the die block 110 to facilitate the separation of the insert plate 150 from the die block 110. To further aid removal, the insert plate 150 includes one or more recesses 151 at a peripheral edge portion to at least partially receive a leverage member, such as a pry bar, to separate the insert plate 150 from the die block 110. In the illustrated embodiment, and as described in detail below, the fill plate 130 also includes fluid couplings 131. The fluid couplings 131 are configured to attach to a fluid source to allow a fluid (e.g., coolant) to flow through the fill plate 130 during operation.

Further details of several components of the assembly 100 are described below with reference to FIGS. 2A-4C. For example, FIG. 2A is a front view, FIG. 2B is a top view, FIG. 2C is a rear view, and FIG. 2D is a bottom view of the die block 110 shown in FIGS. 1A and 1B. Referring to FIGS. 2A-2D together, the illustrated die block 110 includes the fastener openings 176 configured to receive the fasteners 170 to attach the insert plate 150 and fill plate 130 as described above. The die block 110 also includes several alignment openings. For example, the die block 110 can include fill plate alignment openings 212 for receiving the corresponding fill plate alignment features 171, as well as first insert plate alignment openings 214 for receiving the corresponding insert plate alignment features 172 described above. The die block 110 can also include second insert plate alignment openings 216 that are configured for receiving corresponding removable positioning members (not shown) for positioning the insert plate 150 proximate to the die block 110 to facilitate alignment of the insert plate 150 on the die block 110. In addition, the die block 110 can further include die block alignment openings 218 for positioning and aligning the die block 110 on a mold base. The die block 110 further includes multiple ejector openings 220 that slidably receive the corresponding ejectors 180 described above. Furthermore, the die block 110 also includes recesses 222 configured to at least partially receive the corresponding biasing members 178 described above.

FIG. 3A is a top view, FIG. 3B is a cross-sectional side view taken substantially along line 3B-3B of FIG. 3A, FIG. 3C is a rear view, FIG. 3D is an enlarged detail view, FIG. 3E is a right side view, FIG. 3F is a left side view, and FIG. 3G is a bottom view of the fill plate 130 shown in FIGS. 1A and 1B. Referring to FIGS. 3A-3G together, the fill plate 130 includes alignment openings 338 configured to receive the fill plate alignment features 171 described above. The fill plate also includes the fastener openings 175 for receiving the corresponding fasteners 174 to attach the fill plate 130 to the die block 110. The fill plate 130 also includes ejector openings 334 that slidably receive the corresponding ejectors 180 described above. In addition, the fill plate 130 includes multiple fluid channels 336 to allow a coolant fluid, such as water, to flow through the fill plate 130 during use.

In another aspect of the illustrated embodiment, the fill plate 130 includes an inclined face 335 extending from a top surface 333 to an interior side surface 337. The side surface 337 includes multiple protrusions or teeth 340 extending laterally away therefrom. The teeth 340 are configured to direct or otherwise promote the flow of the casting material into the assembly 100.

Referring next to the insert plate 150, FIG. 4A is a front view, FIG. 4B is a bottom view, and FIG. 4C is a rear view of the insert plate 150. Referring to FIGS. 4A-4C together, the insert plate 150 includes the alignment openings 173, as well as the recesses 151 at the peripheral edge portion of the insert plate 150 as described above. The insert plate 150 also includes ejector openings 460 that slidably receive the ejectors 180 described above.

According to another aspect of the illustrated embodiment, the insert plate 150 includes the cavity 152 for forming a battery grid. More specifically, when the insert plate 150 is mated against a corresponding insert plate, the cavity 152 becomes enclosed and at least partially defines a closed grid cavity or recess that can be used to cast two battery grids that can be separated after casting. For example, the cavity 152 includes a peripheral frame portion 454, a web or grid portion 456 extending inwardly from the frame portion 152, and a current connector or lug portion 458 extending away from the frame portion 152. One of ordinary skill in the art will appreciate that the shape of the cavity 152 illustrated in the Figures is merely representative of one type of battery grid configuration. In other embodiments, the cavity 152 can be configured to include various battery grid shapes and/or configurations. Moreover, in still further embodiments, the cavity 152 can be configured to form other battery components or other types of components.

In certain embodiments, the insert plate 150 can be made from steel, such as P-20 steel. In other embodiments, however, the insert plate 150 can be made from other materials suitable for mold casting. Moreover, in one embodiment, the insert plate 150 is configured to weigh approximately 8 to 12 pounds, or 10 pounds, and the fill plate 130 is configured to weigh approximately 10 to 14 pounds, or 12 pounds. Accordingly, two insert plates 150 along with two fill plates 130 have a combined weight of approximately 44 pounds. In other embodiments, however, each of these components can have a weight that is greater than or lesser than the values stated above.

Referring to FIGS. 1A-4C, in operation the insert plate 150 and the fill plate 130 are positioned on and removably secured to the die block 110. In some embodiments, a coating, such as a mold release coating as is known in the art, can be applied to the insert plate 150 and the fill plate 130 to facilitate the flow of the casting material, as well as the removal of the casting material from the cavity 152. The assembly 100 is then mated with a corresponding assembly to form a complete battery grid cavity (e.g., two mated cavities 152) between the corresponding insert plates 150. When the die block 110 is in an assembled position proximate to a corresponding die block, these die blocks are accordingly spaced apart from one another by the combined thicknesses of the corresponding insert plates 150. A predetermined amount of casting material, such as molten lead at approximately 900 degrees Fahrenheit, is poured onto the fill plates 130. The casting material flows through the fill plates 130 by gravitational force (e.g., down the inclined face 335 and the internal side face 337 past the teeth 340) into the cavity 152 between the insert plates 150. Once the casting material fills the cavity 152, the casting material solidifies to form the battery grid (or other casting components). During this process, the fill plate 130 can include a coolant flowing therethrough to maintain the fill plates 130 at an appropriate temperature to allow the casting material to solidify between the fill plates 130. Once the casting material solidifies in the insert plates 150 and the fill plates 130, the assemblies 100 are separated and the ejectors 180 remove the casting material from the cavity 152.

The embodiments described herein, including the insert plate 150 that is removably secured to the die block 110, provide several advantages. More specifically, the relatively small size and weight of the insert plate 150 allows operators to easily remove the insert plate 150 to clean, coat, and/or otherwise treat the cavity 152. As noted above, in an embodiment configured to produce battery grids, the combined weight of two insert plates 150 and two fill plates 130 can be approximately 44 pounds, which is significantly lighter than the weight of a single die block 110. This reduction of weight can provide significant savings when shipping the insert plate 150 and/or fill plate 130 to be cleaned, coated, or otherwise treated. Moreover, in embodiments where the insert plate 150 is a separate component from the fill plate 130, these components can be shipped separately, or otherwise switched out at different intervals. This may be advantages in certain applications, for example, where a coating on each of these components deteriorates at different rates. For instance, the inventors have found that a coating on the cavity 152 in the insert plate 150 may deteriorate or otherwise become unusable more quickly than the same coating on the filler plate 130.

FIG. 5A is a front view of an insert plate 550 configured in accordance with another embodiment of the disclosure. In the illustrated embodiment, the insert plate 550 includes several features that are generally similar in structure and function to the corresponding features of the insert plate 150 described above with reference to FIGS. 1A-4C. For example, the insert plate 550 includes a cavity 552 configured for forming a battery grid. The cavity 552 includes a web or grid cavity portion 556 extending between a peripheral frame portion 554, as well as current collectors or lug portions 558 extending away from the frame portion 554. The grid cavity portion 556 includes multiple cavity channels extending between individual grid features 580 of the insert plate 550. A coating can be applied to the insert plate 550 to facilitate the flow of the casting material through the grid cavity portion 556, as well as to facilitate the removal of the casting material from the cavity 552.

According to one feature of the embodiment illustrated in FIG. 5A, the insert plate 550 includes multiple vent holes 582 extending through at least some of the corresponding grid features 580. In certain embodiments, the insert plate 550 is configured to be mated with a corresponding insert plate without vent holes to form a complete battery grid cavity (e.g., two mated cavities 552) between the corresponding insert plates. In other embodiments, however, both insert plates can include one or more vent holes. As described in detail below, the vent holes 582 are configured to allow air or other gases to escape from the cavity 552 as casting material (e.g., lead) fills the cavity 552 and/or solidifies in the cavity 552.

FIGS. 5B and 5C are enlarged detail views of portions of the insert plate 550 of FIG. 5A. Referring to FIGS. 5B and 5C together, in the illustrated embodiment the grid features 580 are separated from one another by the channels of the grid cavity portion 556, and the vent holes 582 are positioned in the corresponding grid features 580 of the insert plate 550. The number and/or pattern of the vent holes 582 can be selected to prevent any non-fill areas in the grid cavity portion 556 as casting material fills the cavity 552. For example, during operation the cavity 552 may have one or more non-fill areas in the grid cavity portion 556 created by pockets of air from multiple converging fronts of the casting material. The vent holes 582, however, allow the air to escape from grid cavity portion 556 so that the casting material can completely fill the cavity 552. More specifically, and as described below with reference to FIG. 5D, the air can pass from the channels of the grid cavity portion 556 through the coating to the corresponding vent holes 582 to escape from the cavity 552.

FIG. 5D is an isometric view of a portion of the insert plate 550 of FIG. 5A illustrating how air or gas escapes through the vent holes 582 in the insert plate 550. More specifically, in the illustrated embodiment the insert plate 550 includes the grid cavity portion 556 with multiple grid channels 581 extending between the corresponding grid features 580 (shown in broken lines). The vent holes 582 (shown in broken lines) are positioned in the corresponding grid features 580. As also shown in the illustrated embodiment, a coating 583 is applied to the insert plate 550 over the grid cavity portion 556 and the grid features 580. As explained above, the insert plate 550 is configured to be mated against a corresponding insert plate. More specifically, the grid features 580 of the insert plate 550 are configure to mate against a corresponding insert plate to enclose the grid cavity portion 556 for casting battery parts. Air or gas, represented by arrows 585, can accordingly escape from the grid channels 581 in the grid cavity portion 556 by passing through the coating 583 to the reach the vent holes 582 in the grid features 580.

FIG. 5E is a rear view of the insert plate 550 illustrating a backside or vent surface 553 of the inset plate 550. The vent surface 553 is configured to contact or mate with a corresponding die block (see, e.g., FIGS. 1A and 1B). In the illustrated embodiment, the vent surface 553 includes multiple vent channels 584 extending an intermediate depth into the insert plate 550. Each vent channel 584 is aligned with one or more vent holes 582 to allow the air to escape from a top portion 586 of the insert plate 552 after passing through the vent holes 582. In the illustrated embodiment, each vent channel 584 has a width W that is at least approximately equal to the corresponding cross-sectional dimensions (e.g., diameters) of the corresponding vent holes 582. In other embodiments, however, the width W of each vent channel 584 can be greater than or less than the diameters of the corresponding vent holes 582. For example, in certain embodiments, the vent channels 584 can each have a width W that spans two or more vent holes 582 laterally spaced apart across the insert plate 550.

FIG. 5F is a top view of the insert plate 550. As shown in FIG. 5E, the insert plate 550 has an overall thickness T. Moreover, each of the vent channels 584 has a depth D extending from the vent surface 553 into the insert plate 550. The depth D of each vent channel 584 is configured to be sufficiently deep to allow the air to vent when the insert plate 550 is assembled in a mold assembly. In one embodiment, for example, the depth D can be at least approximately 0.005 inch. In other embodiments, however, the depth can be greater than or less than 0.005 inch.

From the foregoing, it will be appreciated that specific embodiments of the disclosure have been described herein in detail for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the disclosure. Further, while various advantages associated with certain embodiments of the disclosure have been described above in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosure. Accordingly, the disclosure is note limited, except as by the appended claims. 

1. A mold assembly for forming a battery grid for a lead acid battery, the mold assembly comprising: a first subassembly comprising— a first die block; and a first insert plate removably coupled to the first die block adjacent to the first fill plate, wherein the first insert plate includes a first recess; and a second subassembly configured to be removably coupled to the first subassembly, the second subassembly comprising— a second die block; and a second insert plate removably coupled to the second die block adjacent to the second fill plate, wherein the second insert plate includes a second recess, and wherein the first insert plate contacts the second insert plate and the first and second recesses at least partially define a grid cavity configured to receive a flowable material for forming a battery grid when the first subassembly is coupled to the second subassembly.
 2. The assembly of claim 1, further comprising: a first fill plate removably coupled to the first die block; and a second fill plate removably coupled to the second die block, wherein the first fill plate contacts the second fill plate when the first subassembly is coupled to the second subassembly.
 3. The assembly of claim 1 wherein: the first die block includes a first ejector opening; the first insert plate includes a second ejector opening that is aligned with the first ejector opening when the first insert plate is coupled to the first die block; and the assembly further comprises an ejector that is movable through the first and second ejector openings to eject a finished battery grid from the first recess.
 4. The assembly of claim 1, further comprising at least one biasing member positioned between the first die block and the first insert plate when the first insert plate is coupled to the first die block, wherein the biasing member urges the first insert plate away from the first die block to facilitate separation thereof.
 5. The assembly of claim 1 wherein: the first recess includes a peripheral frame portion and multiple grid channels extending within the peripheral frame portion; and the first insert plate includes multiple grid features positioned between adjacent grid channels.
 6. The assembly of claim 5 wherein the first insert plate includes multiple vent holes passing through corresponding grid features, and wherein the individual vent holes are configured to allow gas to escape from the cavity as the flowable material fills the cavity.
 7. The assembly of claim 6 wherein the first insert plate includes a first surface that contacts the first die block and a second surface opposite the first surface that contacts the second insert plate in the assembled position, and wherein the first surface includes one or more vent channels extending at least partially therethrough, wherein the one or more vent channels are aligned with one or more corresponding vent holes.
 8. The assembly of claim 7 wherein individual vent channels have a width that is approximately the same as a cross-sectional dimension of the corresponding one or more vent holes.
 9. The assembly of claim 1 wherein: the first die block includes an alignment features extending away therefrom; and the first insert plate includes an alignment opening that receives the alignment feature when the first insert plate is coupled to the first die block.
 10. The assembly of claim 1 where in the first fill plate comprises: a body; and a fluid channel extending through at least a portion of the body and configured to receive a fluid different than the flowable material for transferring heat to or from the body.
 11. A battery grid manufacturing assembly comprising: a first die block; a second die block movable relative to the first die block between a first position at least proximate to the first die block and a second position spaced apart from the first die block; a first insert plate having a first side removably coupled to the first die block and a second side opposite the first side, wherein the second side includes a first recess; and a second insert plate having a third side removably coupled to the second die block and a fourth side opposite the third side, wherein the fourth side includes a second recess, and wherein when the second die block is in the first position the first and second recesses define a grid cavity for forming a battery grid.
 12. The assembly of claim 11, further comprising: a first fill plate removably coupled to the first die block adjacent to the first insert plate; and a second fill plate removably coupled to the second die block adjacent to the second insert plate, and wherein the second die block is in the first position the first and second fill plates are positioned to receive a flowable material and introduce the flowable material into the grid cavity.
 13. The assembly of claim 11 wherein: each of the first and second recesses includes a plurality of grid channels; and each of the first and second insert plates includes a plurality of grid features extending between adjacent grid channels in the corresponding first and second recesses.
 14. The assembly of claim 13 wherein at least one of the first and second insert plates includes a plurality of vent holes aligned with individual corresponding grid features.
 15. The assembly of claim 14 wherein the at least one of the first and second insert plates includes a plurality of vent channels in the first side, and wherein individual vent channels are aligned with corresponding vent holes in the grid features of the first insert plate.
 16. The assembly of claim 11, further comprising: a first alignment feature extending from the first die block and through at least a portion of the first insert plate when the first insert plate is coupled to the first die block; and a second alignment feature extending from the second die block and through at least a portion of the second insert plate when the second insert plate is coupled to the second die block.
 17. The assembly of claim 11 wherein when the second die block is in the second position the second die block is spaced apart from the first die block by a distance that is approximately equal to a combined thickness of the first and second insert plates.
 18. A method of making a battery grid, the method comprising: releasably securing a first insert plate to a first die block, the first insert plate having a first recess in a first surface opposite the first die block; releasably securing a second insert plate to a second die block, the second insert plate having a second recess in a second surface opposite the second die block; coupling the first die block at least proximate to the second die block in a molding position, wherein in the molding position the first surface of the first insert plate mates with the second surface of the second insert plate and the first and second recesses at least partially define a battery grid cavity; introducing a casting material into the battery grid cavity; and allowing the battery grid material to at least partially solidify in the battery grid cavity.
 19. The method of claim 18, further comprising: removably securing a first fill plate to the first die block adjacent to the first insert plate; removably securing a second fill plate to the second die block adjacent to the second insert plate, wherein in the molding position the first fill plate mates with the second fill plate and the first and second fill plates at least partially define a fluid opening; and wherein introducing the casting material comprises introducing the casting material into the grid cavity via the fluid opening.
 20. The method of claim 18 wherein after allowing the battery grid material to at least partially solidify, the method further comprises: removing the at least partially solidified battery grid material from the battery grid cavity; and removing at least one of the first and second insert plates from the corresponding first and second die blocks.
 21. The method of claim 18, further comprising allowing the battery grid cavity to vent while introducing the casting material into the battery grid cavity.
 22. The method of claim 18 wherein after allowing the battery grid material to at least partially solidify, the method further comprises ejecting the at least partially solidified battery material from at least one of the first and second recesses by contacting the at least partially solidified battery material with an ejector that moves through the corresponding first or second insert plates. 